The purpose of this study is to investigate the possibly efficacy and safety of new compounds applied to the treatment of certain disorders of movement, and to employ drugs as tools to analyse the physiological and pharmacological mechanisms mediating various motor deficits. The diseases studied have included Parkinsonism, Shy-Drager Syndrome, Progressive Supranuclear Palsy and, for cerebellar disturbances, multiple sclerosis. The drugs investigated are ergot derivatives with dopaminergic properties (bromocriptine, lergotrile and CF-25-397), agents which increase GABA levels (sodium valproate), and opioid antagonists (naloxone and naltrexone). The results indicate that several dopaminergic ergot derivatives are active antiparkinson agents, particularly useful in managing patients with "on-off" reactions. Bromocriptine causes less dyskinesia than levodopa, but more severe psychiatric reactions. Lergotrile has similar therapeutic properties, but induces disturbances in liver function tests in too many patients to allow its introduction into routine therapy. CF 25-397 has no therapeutic action in Parkinsonism. Cross tolerance has been recorded between bromocriptine and lergotrile. Several patients with Shy-Drager syndrome and Progressive Supranuclear Palsy have also been found to benefit from bromocriptine. Sodium valproate has no beneficial effect in Parkinsonism or cerebellar disease. Preliminary studies with the opioid antagonists have failed to reveal any modification of neurological findings. BIBLIOGRAPHIC REFERENCES: Calne, D.B.: Developments in the pharmacology and therapeutics of parkinsonism. Ann. Neurol. 1:111-119, 1977. Calne, D.B., and Klawans, H.L.: Pathophysiology and pharmacotherapy of tremor. J. Pharmac. Ther. C., Vol. 2: 113-123, 1977.